My opinion:
John Cena hasn't stopped working super hard even though he has made it to the top. that's it. So many people will tell you otherwise, but their wrong. Foley made a good point by saying it isn't the title and how long you have it that matters, it's what you give the fans. CM Punk gives the fans 100% (though he kayfabe doesn't), so he'll be remembered. Mick Foley gave 100%, and he is definitely remembered (like he said only 29 days with the title). Cena still puts on excellent promos and matches though he is the top dog and could slack like a motherfucker.

Look at Miz after WM 27; he worked hard to get to the Main Event, and apparently stopped working hard once there. People boo cena for being repetitive, but the old saying, don't fix what isn't broken applies here. He puts out great matches despite not being a great wrestler. He puts out great promos despite not being the strongest on the mic. He consistently delivers when stuff is already given to him. People boo him but at the same time want to back him up.